Investigation of the sublethal effects of some petroleum refinery effluents

Abstract

In Canada, environmental regulations for protection of the biota from the adverse effects of effluents from petroleum refineries have tended to focus on acute toxicity. There is concern those effluents may have other subtle, but still deleterious, long-term effects on aquatic ecosystems. We have used a battery of toxicity tests to assess the acute toxicity, genotoxicity, and chronic toxicity of effluent samples from two Ontario refineries. The test organisms included representatives of the bacterial, algal, plant, cladoceran, and fish communities. The results of our preliminary study indicate that the effluent samples had little acute toxicity to the test organisms. There were indications of some sublethal toxicity to Ceriodaphnia dubia, Panagrellus redivivus, and Pimephales promeIas. One of the effluents inhibited the growth of Selanastrum capricornutum (ICs0 of 59.9%) and Lemna gibba (IC25 of 73.3%) and also caused a 15 percent reduction in the germination of Lactuca sativa seeds. The SOS-Chromotest, a commercially available test that measures the activity of a bacterial DNA repair system, detected genotoxic effects in a single effluent that had been concentrated ten fold. There was no apparent relationship between several chemical parameters and the observed sublethal effects. Further research is needed to establish whether or not the observed toxic effects are typical of effluents from Ontario refineries.

Detecting genotoxic activity in industrial effluents using the SOS Chromotest microplate assay

“…However, petroleum refinery wastewaters are known to carry a variety of mutagenic chemicals (Houk, 1992), but even extracts of these samples were not found to be very potent in comparison to other industrial liquid wastes (McGeorge et al, 1985). And in a study conducted by Sherry et al (1994), one of two petroleum refinery effluents showed genotoxic effects with the SOS Chromotest after having been concentrated ten fold. In the metallurgical plants (15 samples), 10 samples were detected positive without S9 mix and 5 with S9 mix.…”

Use of various acute, sublethal and early life‐stage tests to evaluate the toxicity of refinery effluents

“…Variations in n ‐alkane levels were used to assess the homogeneity of the composite samples and as a measure of the temporal variability of the effluent over the sample collection period. For the duration of the Oncorhyn‐chus mykiss (rainbow trout) embryo and alevin exposures, 150‐L effluent samples were taken at alternating 4‐ and 3‐d intervals from refinery C. On return to the laboratory, the effluents were mixed, redivided, and stored at 4°C [9].…”

“…In a preliminary survey of two Ontario refineries, we used a battery of toxicity tests to assess the acute and sublethal toxicity of effluent samples [9]. That study revealed little evidence of acute toxicity to test organisms from several phyla.…”

“…It is unclear whether those results are typical of Ontario refineries or Canadian refineries in general. Because the full battery of toxicity tests was not used to assess all samples in our earlier two‐refinery study [9], we extended our partial survey by applying an expanded complement of tests to a larger set of samples. A temporal series of samples was collected from one refinery to describe temporal variation, and effluents from three refineries were tested to describe inter‐refinery variation.…”

The effect of different holding conditions for environmental monitoring with caged rainbow trout (Oncorhynchus mykiss)

“…One way to achieve this is to use biomarkers in fish. 3,4 A biomarker is defined as a biological response to a disturbance, often on the sub-individual level. Since effects at higher hierarchical levels most often are preceded by alterations at lower levels, sub-individual biomarkers can be considered early warning signals of effects on the population or ecosystem levels.…”